Brake control minimizing the number of brakes activated and optimizing wear conditions

Abstract

A braking system for a vehicle having wheels provided with braking devices, the system causing carbon brakes to wear less than do conventional systems. According to the invention, the system is provided with: an adjustable member for voluntary actuation of braking and actuatable by the driver; a transducer controlled by the adjustable member for voluntary actuation of braking, and delivering a first signal representative of the adjustment of the adjustable member as set by the driver to obtain desired deceleration of the vehicle; a computer which controls the braking devices; and a first link connecting the transducer to the computer to transmit the first signal thereto; wherein the computer includes: first calculation device connected to the first link, receiving the first signal, and responding thereto by supplying a second signal representative of a minimum number D of braking devices that should be in the activated state to obtain the desired deceleration; and second calculation device which respond to the second signal to draw up a first list of D identities of braking devices that ought to be in the activated state, the computer using the first list to activate the D braking devices.

I claim: 
     
       1. A system for controlling the braking devices of a vehicle driven by a driver and having a plurality of wheels provided with carbon disk brakes controlled by braking devices, said system being provided with: an adjustable member for voluntary actuation of braking and actuatable by the driver;   a transducer controlled by said adjustable member for voluntary actuation of braking, and delivering a first signal representative of the adjustment of said adjustable member as set by the driver to obtain desired deceleration of said vehicle;   a computer which controls said braking devices; and   a first link connecting the transducer to said computer to transmit said first signal thereto;   said computer includes:   first calculation means connected to said first link, receiving said first signal, and responding thereto by supplying a second signal representative of a minimum number D of braking devices that ought to be in the activated state to obtain the desired deceleration; and   second calculation means which respond to said second signal to draw up a first list of D identities of braking devices that ought to be in the activated state, said computer using said first list to activate said D braking devices.   
     
     
       2. A system according to claim 1, for a vehicle provided on each wheel with a skid detector for detecting wheel skid on the ground, wherein said computer includes: third calculation means connected to each of the outputs of the plurality of said skid detectors, and suitable for calculating the number of skids per wheel during a determined duration; and   fourth calculation means receiving said skid numbers, and suitable for detecting the existing of at least N wheels, each presenting at least M skids, where N and M are integers not less than 1, and supplying a third signal indicating that such skids exist to said second calculation means, said second calculation means then increasing said number D of braking devices that ought to be in the activated state to raise it to a higher number Di, the size of said increase depending on the pair of values M and N.   
     
     
       3. A system according to claim 2, wherein said fourth calculation means is suitable for detecting the simultaneous existence both of at least N1 wheels, each presenting at least M1 skids, where N1 and M1 are integers not less than 1, and of at least N2 wheels each presenting M2 skids, where N2 and M2 are integers not less than 1, and supplying a fourth signal representative of the existence of such skids to said second calculation means, said second calculation means then increasing said number D of braking devices that ought to be in the activated state to raise it to a number D2j that is at least two units greater than D, the size of said increase depending on the pairs of values M1, N1 and M2, N2. 
     
     
       4. A system according to claim 1, including data input means having an adjustably controllable input suitable for actuation by the driver to enter data relating to the estimated value of the coefficient of friction between the wheels and the ground, the input means transforming said data into a fifth signal representative of said estimated value of the coefficient of friction, said fifth value being transmitted via a second link to said second calculation means which in turn changes, as a function of said fifth signal, the number D or Di of identities of braking devices in said first list to a number F or Fi, where F and Fi are positive integers. 
     
     
       5. A system according to claim 1, wherein said computer includes a table supplying said second calculation means with an ordered second list of identities of said braking devices, said second calculation means selecting the identities of braking devices that are to make up said first list by starting from a predetermined position in said second list, and always running through said second list in the same direction. 
     
     
       6. A system according to claim 1, including a plurality of temperature sensors each associated with a respective brake, wherein the computer includes fifth calculation means receiving data from said temperature sensors and suitable for drawing up a third list of identities of braking devices whose brakes are at temperatures lying in a range between a pre-established minimum temperature value Tmin, and a pre-established maximum temperature value Tmax, and transmitting said third list to said second calculation means which gives priority to the identities of braking devices in said third list when drawing up said first list. 
     
     
       7. A system according to claim 1, including a plurality of temperature sensors each associated with a respective brake, wherein the computer includes sixth calculation means receiving the data from said temperature sensors and suitable for drawing up an ordered fourth list of identities of braking devices whose brakes are at temperatures lying between a pre-established minimum temperature Tmin and a pre-established maximum temperature Tmax, said fourth list being ordered as a function of the difference in temperature between the temperature of the brake under consideration and said minimum temperature Tmin, said sixth calculation means being connected to said second calculation means and supplying it with said fourth list, said second calculation means giving priority to the identities of braking devices in said fourth list when drawing up said first list. 
     
     
       8. A system according to claim 1, including a plurality of temperature sensors each associated with a respective brake, wherein the computer includes seventh calculation means receiving the data from said temperature sensors and suitable for establishing a fifth list of identities of braking devices whose brakes are at temperatures exceeding a pre-established safety maximum temperature TM, and transmitting said fifth list to said second calculation means which is suitable for eliminating identities that appear in said fifth list from said first list of identities of braking devices that ought to be in the activated state, and suitable for adding the same number of identities of braking devices to said first list as the number of identities of braking devices that has just been removed therefrom. 
     
     
       9. A system according to claim 1, including a plurality of temperature sensors each associated with a respective brake, wherein the computer includes eighth calculation means receiving data from said temperature sensors and suitable for detecting when each of the brakes is at a temperature below a rest temperature TR that determines a rest state during a thermal cycle of the brakes, and for transmitting a sixth signal representative of such detection to said second calculation means which responds to receiving such a sixth signal by changing the order in which the identities of the braking devices are entered into said first list. 
     
     
       10. A system according to claim 9, wherein said second calculation means is suitable, on receiving said sixth signal, for modifying said order in which the identities of braking devices are entered into said first list in such a manner that over a large number of thermal cycles, it ensures that each of said braking devices is used first about as often as each of the others. 
     
     
       11. A system according to claim 1, including display means including a display and receiving the number D or F of braking devices that ought to be in the activated state in the absence of skidding from said second calculation means via a third link, which number is a function of said first and fifth signals and also of the number Di or Fi of braking devices actually in the activated state. 
     
     
       12. A system according to claim 1, applied to an aircraft having landing gear including a plurality of pairs of wheels, the wheels in each pair being disposed symmetrically relative to each other about the plane of symmetry of the aircraft, wherein said second calculation means maintains both braking devices of the two wheels of each pair in an identical state, activated or not activated. 
     
     
       13. A system according to claim 1, controlling the brakes of a first vehicle which is coupled to at least one second vehicle having a plurality of wheels provided with carbon disk brakes controlled by respective braking devices, wherein said second vehicle includes a computer controlling the braking devices of said second vehicle and comprising: ninth calculation means similar to said first calculation means connected to said first link to receive said first signal and to respond thereto by supplying an eighth signal representative of a minimum number DA of braking devices of the second vehicle that ought to be in the activated state to obtain the desired deceleration; and   tenth calculation means similar to said second calculation means and responsive to said eighth signal to draw up a sixth list including DA identities of braking devices of the second vehicle that ought to be in the activated state, said computer of the second vehicle using said sixth list for activating said DA braking devices of the second vehicle.   
     
     
       14. A system according to claim 13, in which each of the wheels of the first and second vehicles is provided with a respective skid detector, and in which the computer of said first vehicle includes: third calculation means connected to each of the outputs of the plurality of said skid detectors relating to the wheels of the first vehicle and suitable for calculating the number of skids of each wheel of said first vehicle during a determined duration; and   fourth calculation means receiving said skid numbers and suitable for detecting the existence of at least N wheels, each presenting at least M skids, where N and M are integers not less than 1, and providing a third signal representative of the existence of such skids to said second calculation means, said second calculation means then increasing said number D of braking devices that ought to be in the activated state to raise it to a higher number, the size of said increase depending on the pair of values M and N;   wherein said computer of said second vehicle comprises:   eleventh calculation means identical to said third calculation means and connected to each of the outputs of the plurality of said skid detectors relating to the wheels of the second vehicle and suitable for calculating the number of skids of each wheel of said second vehicle during said determined duration; and   twelfth calculation means identical to said fourth calculation means and receiving said numbers of skids relating to the wheels of the second vehicle, and suitable for detecting the existence of at least N wheels each having at least M skids, and supplying said tenth calculation means of the computer of the second vehicle with a ninth signal representative of the existence of such skids of the wheels of the second vehicle, said tenth calculation means then increasing said number DA of braking devices of the second vehicle that ought to be in the activated state to raise it to a higher number DiA, the size of said increase depending on the pair of values M and N.   
     
     
       15. A system according to claim 14, in which the computer of said first vehicle includes fourth calculation means suitable for detecting the simultaneous existence both of at least N1 wheels each presenting at least M1 skids, where N1 and M1 are integers not less than 1, and also of at least N2 wheels each presenting M2 skids, where N2 and M2 are integers not less than 1, and supplying a fourth signal representative of the existence of such skids to said second calculation means, said second calculation means then increasing said number D of braking devices that ought to be in the activated state to raise it to a number D2f that is at least two units greater than D, the size of said increase depending on the pairs of values M1, N1 and M2, N2; wherein the computer of the second vehicle includes twelfth calculation means similar to the fourth calculation means and suitable for detecting the simultaneous existence both of at least N1 wheels each presenting at least M1 skids, where N1 and M1 are integers not less than 1, and also of at least N2 wheels each presenting M2 skids, where N2 and M2 are integers not less than 1, and supplying a tenth signal representative of the existence of such skids to said tenth calculation means, said tenth calculation means then increasing said number DA of braking devices that ought to be in the activated state to raise it to a number D2jA which is at least two units greater than DA, the size of said increase depending on the pairs of values M1, N1 and M2, N2.   
     
     
       16. A system according to claim 13, including data input means having an adjustably controllable input suitable for actuation by the driver to input data relating to the estimated value of the coefficient of friction of the wheels on the ground, and which transforms said data into a fifth signal representative of said estimated value of the coefficient of friction, said fifth signal being transmitted by a second link to said second calculation means of the computer of the first vehicle which modifies the number of identities of braking devices of said first list of the first vehicle as a function of said fifth signal; wherein said second link is connected to the tenth calculation means which modifies the number DA of identities of braking devices of said sixth list as a function of said fifth signal.   
     
     
       17. A system according to claim 13, in which each of the wheels of the first and second vehicles is provided with a temperature sensor and in which the computer of said first vehicle includes fifth calculation means receiving the data from said temperature sensors of the wheels of the first vehicle and suitable for drawing up a third list of identities of braking devices of the first vehicle in which the brake is at a temperature lying between a pre-established minimum temperature Tmin and a pre-established maximum temperature Tmax, and for transmitting said third list to said second calculation means, which second calculation means gives priority to the identities of the braking devices in said third list when drawing up said first list of the first vehicle; wherein the computer of the second vehicle includes thirteenth calculation means similar to the fifth calculation means receiving the data from said temperature sensors of the wheels of the second vehicle and suitable for establishing an eighth list including the identities of the braking devices of the second vehicle whose brakes are at temperatures lying between a pre-established minimum temperature Tmin and a pre-established maximum temperature Tmax, and for transmitting said eighth list to said tenth calculation means, said tenth calculation means giving priority to the identities of braking devices in said eighth list when drawing up said sixth list.   
     
     
       18. A system according to claim 13, including display means comprising a display receiving both the number D of braking devices that ought to be in the activated state in the absence of skidding of the wheels of the first vehicle from said second calculation means of the computer of the first vehicle via a third link, which number is a function of said first and fifth signals, and also receiving the number Di or Fi of braking devices actually in the activated state; wherein:   said third link is connected to the tenth calculation means; and   said display means is suitable for displaying both the number DA or FA of braking devices of said second vehicle that ought to be in the activated state in the absence of skidding of the wheels of the second vehicle, and also the number DiA or FiA of braking devices actually activated in said second vehicle.   
     
     
       19. A system according to claim 13, including: remote control means suitable for receiving and using telemetry data and for emitting remote control commands; and   a two-way bus connected to said remote control means and to said computer of each vehicle, each of said computers being suitable for emitting telemetry data over said bus and for receiving and using remote control commands thereover.